Steering wheel cover

Abstract

A steering wheel cover (5) is described that is suitable for being attached to at least a portion of a rim core of a vehicle steering wheel. This steering wheel cover (5) comprises a flexible element (10), a first seam, and a second seam. The flexible element has a first surface (11), a second surface, a first edge, and a second edge. The first seam extends along the first edge, and the second seam extends along the second edge, each seam comprising a plurality of thread segments located on the side of the first surface. To facilitate a subsequent lacing process, at least one of the two seams has thread segments of a first type (22a) in a regular pattern, the length of which exceeds the distance between the seam holes between which the respective thread segments extend.

Description

[0001] The invention relates to a steering wheel cover according to the preamble of claim 1, a method for producing such a steering wheel cover according to claim 9 and a steering wheel with such a steering wheel cover according to claim 10.

[0002] It is known from the prior art of automotive technology to provide a steering wheel wrap around a rim core of a steering wheel body such that the outer surface of the rim of this steering wheel (or at least a portion thereof) is defined by this steering wheel wrap. Such steering wheel wraps are used particularly in luxury vehicles to give the rim a better feel and / or appearance. Such a steering wheel wrap consists of a flexible element, which can be made of natural leather, for example, but it is also known to manufacture this flexible element from another material, such as artificial leather or another suitable synthetic material or plastic. In its original state (not yet applied to a rim core), the flexible element is typically a flat element with a first surface, a second surface running parallel to the first surface, and two edges.In the geometrically simplest embodiment, the flexible element is a rectangle, with the first and second edges forming the longer edges of this rectangle. It is possible to provide a single flexible element to cover substantially the entire rim core. In this case, the flexible element must generally have at least one recess and / or projection at the location of the at least one spoke of the steering wheel body that connects the rim core to a hub area, or a specific shape attached to the rim. In other embodiments, it is also possible to provide more than one flexible element for the rim core or to cover only part of the rim core with a flexible element. In these cases, the flexible element can have the shape of a simple rectangle.

[0003] To attach the flexible element to the crown core in a final assembly step, a first seam is applied along the first edge and a second seam is applied along the second edge to the flexible element. This can easily be done while the flexible element is still flat. Alternatively, it may also be considered to connect several flexible elements together before the first and second seams are applied. Each seam comprises a plurality of thread sections located on the first surface side, with each thread section extending between two adjacent seam holes extending through the flexible element. Frequently, but not necessarily, each seam comprises two threads: an "upper" thread forming the just-mentioned thread sections extending along the first surface, and a "lower" thread forming additional thread sections extending along the second surface.The pre-product created by attaching the first seam and the second seam to the flexible element is called a steering wheel cover. Such a steering wheel cover can also be referred to as a "shell," "skin," or "composite skin." It can consist of one or more pieces; if the steering wheel cover consists of several pieces, these are usually sewn together.

[0004] During the final assembly mentioned above, this steering wheel wrap (i.e., its flexible element) is wrapped around the rim core so that the first edge and the second edge of the flexible element are tightly aligned (usually on the inside of the rim core). In this state, a lacing thread connecting the first and second seams is manually applied. This final assembly step is very time-consuming and requires skilled personnel.

[0005] Based on this prior art, the object of the invention is to provide a modified steering wheel cover that can be more easily attached to the rim core. In other words, the object of the invention is to provide a steering wheel cover in which the lacing process can be simplified.

[0006] This object is achieved by a steering wheel cover having the features of claim 1. A method for producing such a steering wheel cover is specified in claim 9, and a steering wheel with such a steering wheel cover is specified in claim 10.

[0007] According to the invention, at least one of the seams, preferably both seams, has, in a regular pattern, thread sections on the first surface side that have a greater length (longer than a thread section of a standard seam). These thread sections are referred to as "thread sections of a first type." In other words, at least the first seam or the second seam comprises, in a regular pattern, thread sections of a first type whose length exceeds the distance between the seam holes between which the respective thread section extends. It has been found that such thread sections of the first type can be laced through much more easily with a lace thread, so that the lacing process and thus the final assembly step are simplified overall.This simplification allows the final assembly step to be carried out more quickly and / or by less qualified personnel and / or at least partially by a machine, in particular a robot.

[0008] It has further been found that the attachment of the lacing thread works best when the length of the thread sections of the first type exceeds the distance between the two stitching holes above a certain ratio, in particular above a ratio of 1.1 to 1, preferably above 1.3 to 1. Furthermore, it is preferred if the ratio is not too large, so that in preferred embodiments the ratio is between 1.1 to 1 and 2.3 to 1, or, in other words: the length of a thread section of the first type exceeds the distance between the two seam holes between which the thread section extends, preferably by at least 10%, preferably between 10% and 130%.

[0009] To further improve handling when attaching the lacing thread, it may also be preferable to use a rather stiff thread, so that—as long as the steering wheel cover is not attached to a rim core by means of a lacing thread—the thread sections of the first type are loop-shaped and / or extend away from the first surface and preferably lie in a plane extending perpendicular to the first surface. In this configuration, the thread sections of the first type can be easily looped through by a lacing thread without the need for a tool to pull the thread section away from the flexible element.

[0010] In a first preferred embodiment, all thread sections are thread sections of the first type.

[0011] In a second preferred embodiment, at least the first seam or the second seam additionally comprises, in a regular pattern, thread sections of a second type, the length of which essentially corresponds to the distance between the seam holes between which the respective thread sections extend, or in other words: standard thread sections. In this second embodiment, it is often preferred for thread sections of the first type and thread sections of the second type to alternate, so that a uniform lacing pattern can be easily created.

[0012] The two embodiments just described result in different lacing patterns, so that, among other things, different optics can be created.

[0013] In most applications, it is preferred that the first and second seams have the same pattern to create a consistent lacing pattern.

[0014] A preferred method for producing such a steering wheel cover comprises the following steps: - Providing the flexible element, - sewing the first seam and the second seam, wherein sewing a seam comprises applying a thread - also called upper thread - from the first surface side by means of an oscillating needle, and - positioning a removable spacer element at the location where a thread section of the first type is created.

[0015] If this method is chosen, a standard sewing machine can be used.

[0016] An alternative to this preferred manufacturing method is to adjust the tension applied to the thread during the sewing process such that, without a removable spacer element, thread sections of a first type are formed in a regular pattern, the length of which exceeds the distance between the seam holes between which the respective thread section extends. These thread sections of a first type, whose length exceeds the distance between the seam holes between which the respective thread section extends, can also be referred to as loose stitches.

[0017] Another alternative is to use a movable hook on the sewing machine arranged to catch the thread after piercing a first stitching hole, to pull on the thread and form the thread sections of the first type before piercing a second stitching hole.

[0018] It is possible to use a variety of removable spacers and place them at the locations where the first-type thread sections are to be created. After the sewing process is complete, the spacers are removed again.

[0019] A steering wheel according to the invention comprises a rim, the rim comprising a rim core, a covering wound around this rim core as just described, and a lacing thread connecting the first seam and the second seam of the covering.

[0020] In order to fully exploit the advantages of the invention, it is preferred that the lacing thread extends exclusively between thread sections of the first type.

[0021] Since it is generally not desirable for thread sections to extend away from the flexible element after the last assembly step, it is further preferred that all thread sections of the first type are tied by the lacing thread.

[0022] The invention will now be described in more detail with reference to preferred embodiments and the figures. The figures show: Fig. 1 a schematic plan view of a steering wheel body, Fig. 2 is a schematic plan view of a portion of a flexible element of a steering wheel cover, Fig. 3 sewing a first seam to the flexible element of Fig. 2 in a schematic, not to scale sectional view, Fig. 4 a side view of the steering wheel cover in a schematic, not to scale representation, Fig. 5 the detail D from Fig. 4 (essentially a seam section of the first type), Fig. 6 a plan view from direction R2 in Fig. 4, Fig. 7 a sectional view along the plane AA in Fig. 1 and the steering wheel cover from Fig. 6, which is wrapped around the wreath core, before attaching a lacing thread, Fig. 8 a view from direction R3 in Fig. 7, Fig. 9 what is in Fig. 8 is shown after a lacing thread has been attached, in an enlarged view, Fig. 10 a second embodiment of a steering wheel cover in a representation according to Fig. 4, and Fig. 11 the embodiment of Fig. 10 in a representation according to Fig. 9 (after the steering wheel cover has been wrapped around the rim core and a lacing thread has been attached).

[0023] Fig. Figure 1 shows a steering wheel body 50 with a hub, two spokes, and a rim core 52. A steering wheel with two spokes is shown here, but the invention can of course be applied to any steering wheel with a rim. In most steering wheels, the rim is a closed circle, but the invention is not limited to this type of steering wheel. The rim can also be "open," as has been proposed in the prior art.

[0024] Fig. Figure 2 shows a flexible element 10 which is a precursor of a steering wheel cover intended to be applied to the rim core 52 of the Fig. 1. In the simplest geometric example, this flexible element 10 is an elongated rectangle, but more complex shapes are also possible to accommodate the shape of the rim core 52. In any case, the flexible element 10 has a first edge 10a and a second edge 10b, a first surface 11 and a second surface 12 (see also Fig. 3). Typically, the first edge 10a and the second edge 10b are parallel to each other, at least in sections. The thickness of the flexible element 10 is generally small in relation to its length and width. A typical material for the flexible element 10 is leather, but artificial materials, such as so-called synthetic leather, can also be used. In some embodiments, the flexible element 10 can be elastic to a certain degree, but in most embodiments, the flexible element has sufficient elasticity to be wound onto the rim core 52 without any visible defect.

[0025] In order to prepare the flexible element 10 for mounting on the crown core 52, a first seam 20 (visible in Fig. 6) to the flexible element 10 along its first edge 10a and a second seam 30 (visible in Fig. 6) is attached to the flexible element 10 along its second edge 10b. As a rule, both seams 20, 30 are of the same type, so that in the following only the production of the first seam 20 with regard to the Fig. 3 is described.

[0026] Fig. Figure 3 shows the production of the first seam 20 using a "classic" sewing machine in a schematic representation. This first seam 20 consists of a plurality of seam holes 21, which are created by an oscillating needle 60 of the sewing machine, an upper thread 22, and a lower thread 25. As known from the prior art, the upper thread 22 is guided through a hole in the oscillating needle 60, and the lower thread 25 is unwound from a spool 64 and connected to the upper thread 22 by means of a rotatable hook 62. Transport means for transporting the flexible element 10 in the transport direction T are provided, but in Fig. 3 is not shown. This is a very well-known process, so it need not be described in detail here.

[0027] After the seam has been applied, the upper thread 22 is divided into a plurality of thread sections 22a, each thread section extending between two adjacent seam holes 21. Without additional measures, these thread sections would extend flat along the first surface 11 of the flexible element 10, so that the length of each thread section would essentially correspond to the distance between the two seam holes 21. According to the invention, however, removable spacer elements 70 (here in the form of rods or the like) are arranged on the first surface 11 before the sewing process. Due to these spacer elements 70, the respective thread sections - referred to as thread sections 22a of the first type - are significantly longer than the distance between the respective adjacent seam holes 21 (see in more detail Fig. 7). The factor of this extension naturally depends on the geometry of the removable spacer elements 70, in particular on their height. Furthermore, the tension exerted on the threads and the number of stitches formed before the removal of the removable spacer elements 70 may influence this factor. Fig. 3, all thread sections (i.e., the thread sections of the first thread located on the side of the first surface 11 of the flexible element 10) are thread sections 22a of the first type. Preferably, the length of each thread section of the first type 22a exceeds the distance between the two suture holes between which it extends by a factor of at least 1.3. Typically, the distance between two suture holes can be between 5 and 10 mm, and the maximum distance between the thread and the flexible element 10 can be between 2 and 4 mm when the thread sections 22a of the first type extend perpendicular to the first surface 11.

[0028] The Fig. 4 and Fig. 6 show the steering wheel cover 5 (i.e., the flexible element 10 after the first seam 20 and / or the second seam 30 have been applied thereto along its first edge 10a and its second edge 10b, respectively). As already mentioned, the first seam 20 and the second seam 30 are of the same type. This means that in the first embodiment, all thread sections 22a, 32a are thread sections of the first type.

[0029] Preferably, a sufficiently stiff upper thread is used so that the thread sections 22a, 32a of the first type extend away from the first surface 11 and form loops.

[0030] Fig. 7 shows the crown core 52 from Fig. 1 in a sectional view along the plane AA in Fig. 1 and the flexible element 10 from the Fig. 4 and Fig. 6, which is wrapped around it so that the first edge 10a and the second edge 10b lie against each other or are arranged in close proximity with a small gap therebetween.

[0031] Fig. 8 shows the Fig. 7 parts shown in the view from direction R3 in Fig. 7.

[0032] In a final assembly step, a lacing thread 40 is guided in a zigzag pattern through the thread sections 22a of the first type of the first seam 20 and the thread sections 32a of the first type of the second seam 30. The looped shape of the thread sections 22a, 32a of the first type significantly simplifies this lacing process, so that it can be performed by a human with less effort and in a shorter time. In particular, if the threads (here the upper threads) are relatively stiff, so that the looped thread sections 22a, 32a extend away from the first surface 11, the process can be even more highly automated, so that at least part of this final assembly can be performed by a robot.

[0033] The Fig. 10 and Fig. 11 show a second embodiment. Here, only every second thread section is a thread section 22a, 32a of the first type, and between each thread section 22a, 32a of the first type there is a thread section 22b, 32b of the second type. The thread sections 22b, 32b of the second type are designed like conventional thread sections, i.e., their length essentially corresponds to the distance between the two adjacent stitching holes 21, 31. Of course, any other regular pattern can also be created, for example, such that only every third thread section is a thread section of the first type, etc.

[0034] Fig. 11 shows a preferred lacing pattern for a steering wheel cover 5 as shown in Fig.10. Here, the seam holes 21, 31 are aligned, but the thread sections 22a of the first type of the first seam 20 are offset from the thread sections 32a of the first type of the second seam 30. The lacing thread is also laced only through thread sections of the first type, so that the same advantages apply as in the first embodiment.

[0035] It can therefore be seen that the final assembly step can be significantly simplified by modifying the seams according to the invention. List of reference symbols 5 Steering wheel cover 10 flexible element of the casing 10a first edge 10b second edge 11 first surface 12 second surface 20 first seam 21 seam hole 22 upper thread 22a Thread section of the first type 22b Thread section of the second type 25 bobbin thread 30 second seam 31 seam hole 32 upper thread 32a Thread section of the first type 32b Thread section of the second type 40 lace threads 50 steering wheel bodies 52 crown core 60 oscillating needle 62 rotating hook 64 reels 70 removable spacer element (rod)

Claims

[1] Steering wheel cover (5) adapted to be attached to at least a part of a rim core (52) of a vehicle steering wheel, the steering wheel cover comprising: - a flexible element (10) having a first surface (11), a second surface (12), a first edge (10a) and a second edge (10b), - a first seam (20) extending along the first edge (10a) and a second seam (30) extending along the second edge (10b), each seam (20, 30) comprising a plurality of thread sections arranged on the side of the first surface, each thread section extending between two adjacent seam holes (21, 31) extending through the flexible element (10), characterized bythat at least the first seam (20) or the second seam (30) comprises, in a regular pattern, thread sections of a first type (22a, 32a), the length of which exceeds the distance between the seam holes (21, 31) between which the respective thread section extends. [2] Steering wheel cover according to claim 1, characterized by that the length of a thread section of the first type (22a, 32a) exceeds the distance between the two seam holes (21, 31) between which the thread section extends by at least 10%, preferably between 10% and 125%. [3] Steering wheel cover according to claim 1 or claim 2, characterized by that the thread sections (22a, 32a) of the first type are loop-shaped. [4] Steering wheel cover according to one of the preceding claims, characterized bythat the thread sections of the first type (22a, 32a) extend away from the first surface (11) and preferably lie in a plane which extends perpendicular to the first surface (11). [5] Steering wheel cover according to one of the preceding claims, characterized by that all thread sections are thread sections of the first type (22a, 32a). [6] Steering wheel cover according to one of claims 1 to 4, characterized by that at least the first seam (20) or the second seam (30) additionally has, in a regular pattern, thread sections of a second type (22b, 32b), the length of which is substantially equal to the distance between the seam holes (21, 31) between which the respective thread section extends. [7] Steering wheel cover according to claim 6, characterized by that thread sections of the first type (22a, 32a) and thread sections of the second type (22b, 32b) alternate. [8] Steering wheel cover according to one of the preceding claims, characterized by that the first seam (20) and the second seam (30) have the same pattern. [9] Method for producing a steering wheel cover (5) according to one of claims 1 to 8, comprising the following steps: - Providing the flexible element (10), - sewing the first seam (20) and the second seam (30), wherein sewing a seam comprises applying a thread (22) from the first surface side by means of a needle (60), and - positioning a removable spacer element (70) at the location where a thread section of the first type (22a, 32a) is produced. [10] Steering wheel with a rim, the rim comprising a rim core (52), a sheath (5) according to any one of claims 1 to 8 wound around said rim core (52), and a lacing thread (40) connecting the first seam (20) and the second seam (30) of the sheath (5). [11] Steering wheel according to claim 10, wherein the cover (5) is a cover (5) according to claim 8, characterized by that the lacing thread (40) runs between thread sections of the first type (22a, 32a).

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